Control system



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NvEN'roR Charles P. Croco.

ATTORNEY nited States Patent 2,929,961' VcoN'rRoLsrs'TEM Charles IiCroco, Mount LeblaiionQPl., assignr to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania 'n y Application May 13, 195s,` serial No. 135,042 6 claims. (ci. sis-131) This invention relates generally'y to control systems and, more particularly, to systems` in which push-button switches are utilized for controlling the? operation; of electrically operatedY devices, such asvv contactors and motor starters which are located remotely from the switches. In such' systems indicating lamps are usually installed on switchboards and control panels to provide indication f `the functioning of apparatus located remotely from a switchboardor control panel.

In order to save time in locating control system faults, indicating lamps are so constructed th'at a' lamp can be tested for burn-out b`y pushing on' the' lens of the lamp thereby connecting the lamp to a' test circuit. Furthermore, in order to reduce the ar'nount of apparatus and the-space required for mounting the apparatus, a cornbined indicating lamp and push-button switch has been devised, such as the device described in a co'pending application of A. I. Matiyak et al., Ser'ial'No. 649,873, filed l April 1, 1957. e

An. object of this inventionV is to provide a simplified and improvedcontrolsystem utilizing a combined pushbutton switch and indicating lamp.

Another object of the invention is `to provide for connecting the lamp of a combined push-button switch and indicating lamp across a` power source by depressing the lamp.

A further object of the invention is to provide for utilizing a combined push-button switch and indicating lamp in conjunctionwith push-button switch to perform the functions of starting stopping indicating and testing in a eontrol system' for an electrically operated device. y

Other objects of the invention will be explained fully hereinafter or will be apparent to those skilled in the art. In accordance with one embodiment of the invention, a combined indicating lamp and push-button switch is so connected in a control system in conjunction with a pushbutton V,switch `that the push-button switch is depressed momentarily to energize motorstarter or contactor. The lamp is energized and the starter is held closed by means of a holding circuit established'through auxiliary contact members on the starter. The lamp is depressed to interrupt the holding circuit and deen'ergize the starter. The lamp is also depressed to connect it across a power source to tes-t the lamp for burneout.l

For a better understanding of the nature and objects of the invention, reference may be had to the following detailed description, taken in conjunction with vthe accompanying drawing in which: Y Figure luis a diagrammatic view of a control system embodying the principal features of V'the invention; and

Fig. 2 is a view, partly in section and partly in elevation of a combined push-button switch and indicating lamp utilized in the control system.

Referring to the drawings, and particularly to Fig. 2, the switch shown therein may be of the type described in the aforesaid copending application. The switch comprises a supporting sleeve 10, preferably composed tice of a cast metal, and having a flange 11 at the inner end thereof for engaging the inner side of a supporting panel 12. A sealing disc 13, preferably composed of rubber or the like, is interposed between the ange 11 and the inner surface of the panel 12. The outer end ofthe sleeve 10 is externally threaded for receiving a clamping ring 14 which is adapted to secure the sleeve to the panel 12 when the clamping ring is drawn down tightly. A metal washer 15 may be provided between the clamping rin'g 14 and the outer surface of the panel 12.

The supporting sleeve 1G is provided with a transversely extending web 16 having an opening 17 therein. A housing 18 is slidably disposed in the opening 17. The upper end of the housing 1S is enlarged and threaded internally to receive a lens 19 which may also be used as a push-button. A sealing washer 21 is provided between a shoulder 22 on the lens 19 and the top of the housing 18. A lamp receptacle 23 is disposed inside the housing 18 and a lamp bulb 24 is disposed in the receptacle 23. The bulb 24 is protected by the lens 19. The receptacle 23 is retained in the housing 1S by projections 25 which extend through an opening in the bottom of the housing 18 and also extend through an opening in an operating member 2-6 which is attached to the bottom of the housing 18 by riveting theV projections 25 where they extend through the member 26.

A` compression spring 27 surrounds the housing 18 between a shoulder 28 on the housing 18 and a metal washer 29. A sealing disc or washer 31 is provided around the housing between the metal washer 29 and the web 16 of the sleeve 10 to prevent oil or other material from passing through the opening 17. The spring 27 compresses the sealing disc 31 and biases the housing 18 outwardly. The outward movement of the housing 1S is limited by the operating member 26 which engages the bottom of the sleeve 10.

One leg of an L-shaped bracket 32 is attached to projections 33 on the bottom end of the sleeve 10 by screws 30. A terminal block 34 is attached to the bracket 32. A resistor 35 may be attached to a bracket 36. The bracket 36 may be attached to the terminal block 34. As will be described more fully hereinafter, the resistor 35 may be connected in the circuit for the lamp 24. If desired, a transformer may be utilized in place of the resistor 35 when the lamp is energized with alternating current. The lamp 24 may be connected across the line voltage in case the voltage is not higher than the rated voltage of the lamp.

An enclosed switch 37 is attached to the other leg of the bracket 32 by means of screws 38. The switch 37 is preferably of a double-throw spring-return snap-action type, such as, for example, the switch described in Patent No. 1,960,020. The switch 37 is provided with an operating plunger 39 which is engaged by the operating member 26 to actuate the switch when the lens 19 is depressed. The switch 37 is provided with contact members which control the energization of the lamp 24 as will be described more fully hereinafter.

As shown in Fig. l, a push-button switch 41 may be utilized in conjunction with the combination indicating lamp and pushbutton switch shown in Fig. 2 to control the operation of a motor starter or contacter M which may be utilized to control the energization of an electric motor or other apparatus (not shown). When the kpush-button switch 41 isv depressed, an energizing circuit the coil of the contacter isestablished from the power y conductor L1 through auxiliary contact members Ma of the contactor and the contact members 44 and 45 of the switch 37. Thus, the switch 41 may be released after the contacter M is closed. An energizing circuit for the lamp 24 is also established at this time. yThis circuit extends from the power conductor L1 throughthe auxiliary Contact members Ma, the lamp 24 and the resistor 35 to the conductor L2. Thus, the lamp is lighted to indicate that the contactor M is closed and the load is connected to the line conductors L1, L2 and L3 through main contact members M1, M2 and VM3 of the contactor M.

If it is desired to disconnect the load from the line conductors, the lamp 24 is depressed to actuate the switch 37, thereby opening the circuit through its contact members 44 and 45 which interrupts the holding circuit for the coil `of the contacter M. At the same time Ma opens the circuit to lamp 24, thereby extinguishing the lamp.

If it is desired to test the lamp 24 for burn-out, the lamp is depressed, thereby actuating the switch 37 to establish'a circuit through contact members 46 and 47 of the switch. The lamp 24 is then connected directly across the power conductors Li and L2 in series with the resistor 35. It will be noted that the testing circuit for the lamp 24 does not include the push-button switch 41. Accordingly, the failure of the lamp 24 to light when the testing circuit is closed indicates that the lamp is burned out.

From the foregoing description, it is apparent that .the invention provides a control system which is suitable for controlling the operation of a motor starter or another electrically operated device. By utilizing the combination indicating lamp and push-button switch the amount of apparatus required is reduced. The system provides for aV push to start, "a light for run, a push to stop and a push to test operations. The testing circuit for the indicating lamp is independent of the starting pushbutton and the auxiliary contact members on the motor starter or contactor. Thus, a burn-out of the indicating lamp may be readily detected.

Since numerous changes may be made in the above described construction and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all the matter contained in the foregoing description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. In a control system, in combination, an electrically operated device having an actuating coil, a first switch having contact members for controlling the energization of the coil, a second switch having first contact members for controlling the deenergization of the coil, second contact members on the second switch, a lamp for indicating the functioning of the device, said lamp being movable to actuate said second switch, auxiliary contact members actuated by said device for controlling the energization of the lamp, and said second contact members being actuated by moving said lamp to establish a testing circuit for the lamp independently of said auxiliary contact members.

"2. In a control system, in combination, an electrically operated device having an actuating coil, a first switch having contact members for controlling the energization of the coil, a second switch having contact members for controlling the deenergization of the coil, additional con- `tactmembers on the second switch, a lamp for indicating the functioning of the device, said lampV being movable to actuate said second switch, auxiliary contact members actuated by said device for controlling the energization of the lamp, and said lamp'being movable to establish a testing circuit for the lamp through said additional contact members independently of said auxiliary contact members. U Y,

3. ln a control system, incombination, an electrically operated device having an actuating coil, a first switch having contact members for, controlling the energization of the coil, a second switch having contact members for controlling the deenergization of the coil, additional contact members on the second switch, a lamp for indicating the functioning of the device, said lamp being mov- Lli) able to actuate said second switch, auxiliary contact members actuated'by said device for controlling the energization of the lamp, and said lamp being movable to establish a testing circuit for the-lamp through said additional contact members independently of said first switch and said auxiliary contact members.

4. In a control system, in combination, an electrically operated device having an actuating coil, a first switch having contact members for controlling the energization of the coil, a second switch having tirst contact members for controlling the deenergization of the coil, second contact members on the second switch, a' lamp for indicating the functioning of the device, said lamp being movable to actuate said second switch, auxiliary contact members actuated by said device andA cooperating with the first contact members on said second switch to establish a holding circuit for said device, and said second contact members being actuated by moving said lamp to establish a testing c ircuit for the lamp independently ot the auxiliary contact members and the rst switch. l

5. In a control system, in combination, an electrically operated devic'ehaving an actuating coil, a first switch having contact members for controlling the energization of the coil, a secondV switch Yhaving contact members for controlling the de'energization of the coil, a lamp for indicating the functioning of the device, said lamp being movable to actuate said second switch, auxiliary contact members actuated by said device and connected in series with contact members of said second switch to establish a holding circuit for said device, and said lamp being movableY to establish a testing circuit for the lamp by actuating the second switch independently of said auxiliary contact members and said first switch.

6. In a control system, in combination, an electrically operated device having an actuating coil, a lirst switch having contact members for controlling the energization of the coil, Va second switch having contact members for controlling the deenergization of the coil, a lamp for indicating the functioningV of the device, said lamp being movable to actuate said second switch, auxiliary contact membersactuated by said device to establish an energizing circuit for said lamp, said auxiliary contact members being connected in series with contact members of said second switch to establish a holding circuit for said device, and said lamp being movable to establish a testing circuit for the lamp'by actuating the second switch independently of said auxiliary contact members and said first switch.

References Cited inthe file of this patent UNITED STATES PATENTS 2,449,213 Frederick sept. i4, 194s 2,466,355 Baker Apr. 5V, 1949 2,710,954 Hallerberg et al. June 14, 1955 2,724,822 .Harrington .a NOY. v22, 1955 

